Oil and eye Indicator

Good week yesterday I put angel headlight on the car yesterday and after installing it, when I turned the 2000 xs 206 oil gauge ignition, it went down and down twice but now it goes down after a bit of a stop, or it goes down after over 140, and also yesterday there was no movement on the Speed dial today I tried Speed and the dial has improved.

the speed dial sensor has failed. I have no knowledge for oil